Development and Validation of a Tissue Handling Simulation Using a Grapefruit Model

INTRODUCTION: Simulation-based training is an essential component of surgical education. There is a need for a low-cost simulation model for tissue handling and dissection, a foundational skill in gynecologic and other surgical specialties. A model based on a grapefruit offers a novel approach to simulate tissue dissection. OBJECTIVE: To develop a tissue dissection and handling model and present evidence supporting its face and construct validity as a surgical training tool and effectiveness in improving trainee confidence. METHODS: This prospective pre–post interventional pilot study was conducted at a tertiary academic center. A simulation model focusing on tissue dissection and handling skills was developed using a grapefruit. Two tasks were selected that closely mimic fine dissection, precise tissue handling, and respect for tissue planes. Task 1 required participants to separate the pith, the white spongy layer between the peel and membrane, from the underlying membrane. Task 2 required participants to separate the membrane from the fruit segment itself. The goal for both tasks was to preserve tissue integrity—avoiding entry into the juicy segments—while removing the pith or membrane in one piece. Obstetrics and gynecology residents were compared to experts consisting of urogynecology fellows and attendings. Prior to performing the simulation, participants received standardized instructions, which included a short didactic presentation, written task descriptions, and a demonstration video, then completed a baseline survey assessing confidence in tissue dissection. Tasks were then performed and video-recorded for independent evaluation. Performance was assessed by 2 blinded expert graders using the validated Objective Structured Assessment of Technical Skills (OSAT) system, which evaluates tissue respect, instrument handling, and procedural flow with a maximum score of 40. Face validity was assessed through participant surveys regarding the realism and educational value of the model, while construct validity was determined by comparing OSAT scores between trainees and experts. Mean OSAT scores were calculated for each task. Pre- and post-intervention confidence surveys were compared using chi-square or Fisher’s exact tests, and t-tests were used to compare group performance. A p-value <0.05 was considered statistically significant. RESULTS: Among the 22 participants, there were 17 trainees and 5 experts. Participants were predominantly female (77%) and right-handed (91%). For Task 1, OSAT scores did not significantly differ between trainees and experts (26.8 [SD 4.1] vs 29.8 [SD 3.0], p=0.21). For Task 2, however, experts scored significantly higher than trainees (31.1 [SD 0.8] vs 27.0 [SD 5.9], p=0.012), demonstrating the model’s ability to discriminate between skill levels in more complex tasks. Trainee confidence increased substantially after the simulation, rising from 59% pre-intervention to 94% post-intervention. Nearly all participants, 96% of trainees and 100% of experts rated the model as effective for teaching tissue dissection, supporting face validity of the model. CONCLUSIONS: The grapefruit-based tissue dissection model improved trainee confidence and demonstrated construct and face validity. This simple, low-cost, reproducible simulation tool shows promise for integration into training curricula of gynecologic surgery and plausibly other surgical specialties as a more feasible alternative to animal-based models.Figure 1Figure 2Table 1